<template>
  <div class="person">
    <h1>情况一：监视【ref】定义的【基本类型】数据</h1>

    <h2>dq当前求和为：{{sum}}</h2>
    <button @click="incrementSum">点我sum + 1 </button>
  </div>

</template>

<script setup lang="ts" name="Person">
 import {ref,watch} from 'vue'

 //数据
 let sum = ref(0)

 //方法
 function incrementSum() {
   sum.value += 1
 }
 // 监视
 // watch(谁？ 回调函数) 情况一：监视【ref】定义的【基本类型】数据
 const stopWatch = watch(sum,(newValue,oldValue)=>{
   console.log('sum变化了',newValue,oldValue)
   if (newValue >= 10) {
     stopWatch()
   }
 })
</script>
<style scoped>

.person {
  background-color: skyblue;
  box-shadow: 0 0 10px;
  border-radius: 10px;
  padding: 20px;
}

button {
  margin: 0 5px;
}

li {
  font-size: 20px;
}
</style>